For PSOs there are two significant sources of emergent change and innovation.
First it may be required by a sudden unforeseen crisis.This might be environmental (such
as an earthquake or forest fire), health related (such as the SARS outbreak of 2003
in Hong Kong) or a man-made crisis (such as major fire in an underground railway,
as occurred in London in the 1990s). Now public services have always had to
expect such sudden crisis and much energy is expended on trying to reduce the
likelihood of such a crisis, to predict the likely timing or locality of it, and/or to
develop skills to deal with it (hence the development of such professions as risk
and crisis management). However, the very nature of emergent change means that
it can never be entirely planned for.